The invention relates to a container which can be inserted into a power-supply unit and is intended for the preparation of hot drinks, with a liquid-storage container, an electric heating element arranged therein and a collecting container for the drink prepared, the liquid-storage container having a closure which is arranged in the bottom of the liquid-storage container and opens in a manner not automatically reversible at a predetermined internal pressure of the container, due to the arching outwards of the bottom, which is provided with contacts for the supply of electrical power which are connected to the heating element via an electric lead, and which can be inserted or is inserted into the collecting container in such a way that, in the operating position, the collecting space is essentially below the storage container, and the power supply to the heating element being designed in such a way that it is interrupted when the closure is opened.
Known containers of this type (EP-A-0 382 001) can be introduced into a power-supply unit. A liquid, normally water, is then heated in the container. The heating causes the internal pressure in the container to increase, with the result that the bottom of the liquid-storage container arches outwards and a closure arranged in the bottom opens, with the result that the hot liquid comes into contact with the brewing medium or material to be brewed. The hot drink prepared in this way then collects in the collecting space below the liquid-storage container and can be drunk via a lateral opening or (in the case of a soup) eaten with a spoon after the container has been removed from the power-supply unit and the liquid-storage container has been separated from the collecting container.
In the embodiment already disclosed, the closure has a fixed spike which is surrounded by an opening in the bottom, the said opening being provided with a seal. However, such a seal cannot operate satisfactorily, particularly in the case of prolonged storage.
It is therefore the object of the invention to provide a container which can be sealed off better in the region of the closure.
The solution according to the invention consists in the fact that the closure is formed by an annular projection surrounding an opening of the bottom and by a spike secured in the interior of the liquid-storage container, and in that seals are arranged on the projection and/or spike.
Thus there is no longer a more or less linear sealing face between the bottom and the spike but instead a larger region between the annular projection and the spike, between which suitable seals, especially lip seals or rolling ring seals, are arranged.
A further advantage, that the spike is arranged in the liquid-storage container and not, as in the embodiment already disclosed, outside the latter, consists in the fact that the material to be brewed no longer has to be arranged in a ring around the spike but can have the shape of a cylinder similar to a tablet. A further advantage is the smaller number of individual parts in the assembly of the container, making it possible for this container to be of reusable design and to be refilled for future use, after appropriate cleaning, by the user himself.
Advantageously, a cup-shaped element with the material to be brewed is mounted at the bottom of the liquid-storage container, which element should be mounted releasably if the container is to be filled by the user himself. At the bottom of the annular projection, it is possible to arrange a funnel which widens downwards, allowing the liquid-storage container to be filled more simply with liquid after being turned upside-down. Here, "bottom" always means the side which is at the bottom in the use position.
The funnel can be foldable, as known, for example, from camera lens hoods, thus taking up less space after it has fulfilled its task of enabling the liquid-storage container to be filled more easily with liquid.
A further solution according to the invention is distinguished by the fact that the closure has a seal which can be broken open mechanically. This solution will always be preferred when even the complicated seal described above is inadequate.
The closure can here be a film which seals the opening in the bottom and is destroyed by a spike arranged outside the liquid container when the bottom arches outwards. In this way, the liquid in the liquid container is sealed off hermetically prior to use and remains fresh and clean there for years.
Instead of the one film, it would also be possible here to provide a film bag which firmly seals the opening, in which case the films on both sides of the film bag would then be destroyed by the spike. In this way, the material to be brewed can also remain sealed off hermetically for a very long time.